The present invention relates to an apparatus which is adapted particularly for use with electronic equipment, wherein the apparatus is constructed so as to enable a plurality of circuit boards disposed side-by-side to be firmly held in the apparatus but readily removable therefrom, said apparatus being referred to generally as a magazine.
Magazines of this kind may comprise a backplane on which there has been mounted rows of connector fields or connector strips in predetermined spaced relationship in grooves provided in a lower part and an upper part of the backplane for guiding the circuit boards towards and away from said connector strips, and may further comprise two end walls, wherein the connectors belonging to the connector strips of the backplane and the connectors belonging to the connector strips on the circuit boards can be brought into and out of coaction with one another.
The backplane is in the form of a board which carries a printed circuit where the circuit is normally oriented in several planes and coordinated for coaction with individual electrical connectors provided in the electrical connector strips belonging to the backplane.
The individual connectors in such a connector strip may be connected through the printed circuit on the backplane, or mother board, to other connectors included in another or in several other connector strips to form a bus therebetween, and hence the backplane may also be referred to as a backplane bus.
It can be mentioned at this point that such buses may be referred to as data buses in the transmission of data information, as address buses in the transmission of address information, and so on. The invention includes every type of signal information transmitting bus.
Furthermore, by "bus" as used in the following description is meant that all signal information that occurs thereon shall be available to a plurality of identical or different signal processing units or the like belonging to one or more circuit boards.
Magazines of the kind intended here are normally standardized, having specific breadth and height measurements with regard to the backplane and specific measurements, depth measurements, for usable boards, and having specific distances or spacings between respective boards and therewith between mutually adjacent connector strips in the backplane.
Normally, there is chosen a magazine size which will provide adequate accommodation for the required number of circuit boards and which will subsequently enable a simple extension to be achieved.
The magazine is thus used to position the necessary circuit boards in side-by-side relationship, where each circuit board may carry data processing units, adaptation circuits, memory stores and the like, coordinated to perform a number of functions.
In one application, it may be convenient to coordinate data processing and the central unit on one board, the requisite memory stores on another board, and input ports and output ports on a further board.
In addition to this coordination, the possibility is also afforded of permitting the backplane of the magazine to include one or more buses, such as to enable the functions of one circuit board to coact with the functions of one or more other circuit boards allocated to the own, or local, magazine or to some other magazine.
The invention also relates to a development of the type of magazine that includes a measurement-standardized backplane on which there is mounted a predetermined number of mutually adjacent and mutually spaced elongated, narrow connector fields in the form of connector strips, each of which carries, in rows and columns, connectors in the form of pin connectors (or socket connectors) and are each adapted for firm, but easily released, mechanical and electrical coaction with a corresponding connector field in the form of connector strips which carry rows and columns of connectors in the form of socket connectors (or pin connectors) related to and attached to an edge part of respective circuit boards.
It is known in the case of such magazines to permit part of a number of selected first connector fields to be connected electrically to a first bus, and to permit a part of a number of selected second connector fields to be connected electrically to a second bus.
Several different designs of apparatus and magazines which include a backplane, or mother board, provided with connector fields or connector strips of the aforedescribed kind are known in principle to the art.
Reference can be made in this regard to the electronic apparatus or the magazine illustrated and described in European Patent Application 88111974.7, Publication No. 0,302,351. (See FIG. 1).
In the following description of the earlier known prior art bracketed reference signs have been included by way of reference to corresponding parts in the aforesaid patent publication, where a Figure included in this reference corresponds to FIG. 1 of the instant Patent Application.
The electronic apparatus illustrated and described in the aforesaid European patent publication includes a carrier (a backplane) which supports a number of printed circuit boards, this card carrier including a plurality of contact sites or connector fields (SP1, SP2 . . . SP16), in which different circuit boards (BG1, BG2) can be inserted.
The connector fields with backplane connectors are divided into at least two groups (B1, B2 . . . B7; B10, B11, B12, B13, B14; B20, B21, B22; B30 . . . B33).
The groups of connector fields (B1, B2 . . . B7; B10, B11, B12, B13, B14; B20, B21, B22; B30 . . . B33) are mutually cross-connected by means of cross-connections or buses (LP0, LP1, LP2, LP3).
Corresponding connector fields (ST1, ST2, ST3) having corresponding connectors are attached to one edge of a respective circuit board (BG1, BG2), this edge being positioned at right angles to the insertion direction. When respective circuit boards are inserted to their respective positions, these connectors are electrically connected with selected connector fields and their backplane connectors, and therewith form an electrical connection between circuit board and backplane.
The connector sites or connector fields in the backplane (SP1, SP2, . . . SP16) are primarily intended for two different circuit boards. A first connector field (SP1) coordinated in two rows of connectors, is adapted for coaction with a first circuit board (BG1) having two rows of connector fields (ST1, ST2), a second connector field (SP2) and several thereof are adapted for coaction with a second circuit board (BG2) having a row of connectors (ST3).
The first circuit board (BG1) thus includes two rows of connector fields (ST1 and ST2) and is adapted for coaction with certain selected connector fields in the backplane (B1, B10; B2, B20; B3, B30) and is therewith connected to two buses (LP0 and LP1; LP0 and LP2, LP0 and LP3).
The second circuit board (BG2) includes only one row of connector fields (ST3) and is therewith primarily adapted for coaction solely with certain connector fields (B11, B12; B21, B22) in the backplane for connection to one bus (LP1, LP2).
The aforesaid patent publication also discloses the connection between various circuit boards and the backplane connector fields with the bus connection. In order to function, it is necessary when using one circuit board (BG2) which includes one single coupling field (ST3) having connectors, for said coupling field (ST3) to be always mounted in one first coupling field among several possible coupling fields on the backplane, while when using the second circuit board (BG1) having two coupling fields (ST1, ST2) with connectors, it is necessary always to mount the fields in both a first and a second coupling field.
When considering the features characteristic of the present invention, it can be established that the connector fields, and therewith the circuit board sites, are here coordinated in groups in part-sections of the backplane.
In a left side part-section (B1, B10-B14), The first connector field (B1) is connected to respective first connector fields (B2, B3) for mutually adjacent part-sections (B2, B20-B22; B3, B30-B33).
Remaining connector fields (B10-B14) within respective part-sections (B1; B10-B14) are connected together and connect with a common bus (LP1).
Thus, according to the technique known from this publication, one connector field of the parallel backplane connector fields begins by being adapted for one single bus (B1, LP0), while a plurality of connector fields (SP2, SP3, SP4, SP5) oriented laterally of this one connector field coact with one single second bus (LP1).
Furthermore, it can be seen that when dividing the backplane into the aforesaid part-sections (SP1-SP5, SP6-SP8, SP9-SP12), each first connector field (B1, B2, B3) will connect to one and the same bus (LP0), whereas remaining connector fields (B10, B11, B12, B13, B14) within selected part-sections will all connect to another bus (LP1) allocated to the part-section.
The two adjacent connector fields (B1, B10) of the backplane are intended to be connected to the first bus (LP0) and also to the second bus (LP1) through one single circuit board (BG1).
It will also be seen that the backplane-related connector fields are grouped in three part-sections (B1, B10-B14; B2, B20-22; B3, B30-B33) with a different number of connector fields within each group.
The following publications can be mentioned as further examples of the present standpoint of techniques.
EP-A-0,488,057 PA1 U.S. Pat. No. 5,006,961 PA1 U.S. Pat. No. 4,998,180 PA1 EP-A2-0,266,765
When considering the earlier standpoint of techniques as described above, it will be seen that a problem resides in providing an apparatus or a magazine of the kind mentioned which will enable standardized boards and/or boards of special manufacture to be brought easily into coaction and connection with one or more buses and which will afford a wide choice with regard to the selection of circuit board sites related to the connector fields of the backplane.
Another technical problem is one of realizing the advantages that are afforded by the manufacture of a backplane in which the connector fields are grouped so that a predetermined number of connector fields form a group and so that the number of connector fields is so selected as to form a plurality of groups, and so that each group is allocated the same number of connector fields.
Another technical problem resides in realizing that when the connector fields are grouped thus, the first connector fields of respective each groups shall be joined together and shall be capable of being connected to a first bus, and that the second connector fields of respective each group shall be joined together and shall be capable of being connected to a second bus, and so on when required.
This thus requires the necessary number of bus connections to be distributed symmetrically among a number of groups.
In addition, it will be seen that a technical problem is one of realizing the simplifications that are achieved when adapting the backplane so that one group or a number of groups coacting with one or two buses adapt to the minimum requirement of an anticipated function, but that one or more further groups are prepared within the backplane and within the confines of its measurements so as to enable the functions to be extended, either as a separate function and/or as a redundant function.
In this regard, a technical problem resides in realizing those advantages that are associated with orientating the connector fields within each part-section and the bus orientation belonging to the backplane in a manner such that one section of each first connector field in each group connects to a first bus, and that each second connector field in each group connects to a second bus, and so on when required.
It will also be seen that a technical problem resides in realizing that even if it is possible theoretically to choose a relatively large number of connector fields within each group, the number of connector fields within the groups should, nevertheless, be limited to two or three in the case of a practical application, since this number normally observes the redundancy requirement and similar requirements and provides the largest possible number of groups within a predetermined measurement dimension of the backplane.
A further technical problem resides in the ability to realize the practical simplifications that are afforded when at least a part of the boards used are constructed specifically to present, as a unit, a number of connector fields and a division therebetween which conforms to the number and the division of the connector fields within the group.
It will also be seen that a technical problem is one of realizing the flexibility that is afforded by including two connector fields within each group, one for each bus, thereby enabling a utilized, standardized circuit board within each group to be connected, through its connector field, to one of the two available mutually spaced buses, either with a specifically-constructed circuit board allocated two planes and having two adjacent connector fields therewith affording one of two possible connections to the two buses, so as to obtain a redundant function thereby, for instance.
With regard to apparatus of the aforesaid kind and with regard to affording the aforesaid flexibility, it will be seen that a further technical problem resides in realizing the significance of using as a starting point a measurement-standardized magazine having a measurement-standardized backplane with measurement-accurate connector fields which are spaced apart at a distance which slightly exceeds the breadth of the connector field and to use at least for certain of these connector fields standardized circuit boards which are connectable to a bus, and also to realize the possibilities available when further connector fields are placed between the earlier mentioned standardized connector fields, and that these further connector fields can be connected to one (or more) other buses through the backplane.
Another technical problem resides in realizing the advantages that are associated with such a simple increase in the capacity of the magazine, where this increase in capacity can be readily effected without needing to increase the external dimensions of the magazine, but is able to create a higher degree of use and greater security via a connection to a further bus, while taking into consideration that one such magazine is basically adapted with its backplane for coaction with a number of boards, each being intended for coaction with one single bus.
It will also be seen that a further technical problem is one of realizing that a desired extension of the functions can create conditions for an error interpreting function and/or a redundant function and/or an improvement in transmission capacity.
Another technical problem is one of realizing that this extension can be achieved with the same magazine size and therewith the same size of the backplane used, but with more connector fields packed closer together.
Another technical problem is one of realizing the significance, and also the simplicity, of permitting a number of first selected connector fields to be given odd numbers, and a number of other selected connector fields to be given even numbers in consecutive order allocated to all connector fields when using only two buses, and to join and connect the odd numbered connector fields to a first bus, and to join and connect the even numbered connector fields to a second bus, the pairs of connector fields forming individual groups.
On the basis of the aforesaid technical problems, it will be understood that a technical problem also resides in realizing that conditions for doubling the connector fields can be readily fulfilled by a standardized magazine retailed with standardized circuit boards under the designation "Futurebus +".
It will also be seen that a technical problem resides in realizing the flexibility that will be afforded by the inventive distribution and grouping of the connector fields when using, in a known manner, a circuit board which is constructed of plates disposed in two or more planes with corresponding two or more connector fields coordinated with adjacent edge-parts of said two or more plates, and the corresponding connector fields are adapted for coaction with the connector fields in the backplane for cooperation with a respective bus, and therewith realize that when the connector fields are uniformly spaced, one such circuit board can be caused to coact with all connector fields within a group or with one or more connector fields within adjacent groups.